Opisthokonta: Fungi and Their Role

• Opisthokonta is a supergroup in the domain Eukaryota.
• Fungi and Animals are included in the Opisthokonta supergroup.
• Molecular evidence indicates fungi and animals share a more recent common ancestor than either does with plants.

Contributions of Fungi to Ecosystem

• Fungi act as decomposers, breaking down dead organic matter and recycling nutrients like carbon, nitrogen, and phosphorus into the soil.
• Fungi form symbiotic relationships, including mycorrhizae with plant roots to aid in nutrient absorption, and as lichens with algae or cyanobacteria.
• Fungi are used as food, in fermentation (yeasts for bread and beer), and in medicine (e.g., Penicillium).

Fungal Structures, Distinguishing Features, and Biology

• Hyphae are long, thread-like filaments that make up the mycelium of fungi.
• Mycelium is a mass of hyphae that forms the vegetative body.
• Chitin is the main structural component of the fungal cell wall, distinguishing them from plants.
• Asexual reproduction in fungi occurs via spores, such as conidia and sporangia, while sexual reproduction occurs through specialized fruiting bodies.

Mycorrhizal Fungi & Cordyceps

• Mycorrhizal fungi are symbiotic fungi associated with plant roots, enhancing plant nutrient and water absorption in exchange for carbohydrates.
• Ectomycorrhizal fungi sheath plant roots, while arbuscular mycorrhizal fungi penetrate root cells.
• Cordyceps are parasitic fungi that infect insects or other arthropods, growing inside the host, eventually killing it and releasing spores.

Ascomycota, Basidiomycota, & Lichens – Anatomy and Features

• Ascomycota (Sac Fungi) produce sexual spores (ascospores) in an ascus and reproduce asexually via conidia. Examples include yeasts, truffles, and molds.
• Basidiomycota (Club Fungi) produce sexual spores (basidiospores) on basidia and examples include mushrooms, puffballs, and rusts.
• Lichens are a symbiotic association between fungi and photosynthetic organisms (algae or cyanobacteria) and are classified by their fungal partner (Ascomycota or Basidiomycota). They serve as bioindicators of environmental health.

Relationship Between Plants, Fungi, and Animals

• Plants provide carbohydrates to fungi via mycorrhizal partnerships.
• Fungi decompose organic material and form symbiotic relationships with plants and animals.
• Fungi can be parasitic on animals (e.g., Cordyceps) or form mutualistic relationships, such as in herbivore guts.

Eumetazoa, Bilateria, Vertebrates in Animals

• Eumetazoa are animals with true tissues (excluding sponges).
• Bilateria are animals with bilateral symmetry and cephalization, including most animals.
• Vertebrates are a subgroup within Bilateria that have a backbone/spinal column. Examples include mammals, birds, and reptiles.

Porifera: Types of Cells, Osculum, Suspension Feeders

• Porifera (sponges) are simple, multicellular organisms without true tissues.
• Choanocytes filter food particles from water, while amoebocytes distribute nutrients and secrete spicules.
• Osculum is the opening where water exits the sponge.
• Sponges are suspension feeders, filtering small particles like plankton from water.

Cnidaria: Diploblastic, Tissues, Radial Symmetry, Cnidocytes (Nematocysts), Sedentary and Mobile Forms

• Cnidaria includes jellyfish, corals, and sea anemones.
• Cnidarians are diploblastic, having two germ layers (ectoderm and endoderm) with radial symmetry.
• Cnidocytes (nematocysts) are specialized stinging cells used for prey capture.
• Some cnidarians are sedentary (e.g., corals, sea anemones), while others are mobile (e.g., jellyfish).